For SDK based A/B/n tests, enable visualization of result in Grafana

[kalantar]

Consider exposing raw metrics (instead of just summary metrics) and doing summary metric/best computations in Grafana if possible.

Issues related to Grafana

• Investigate exporting Grafana dashboard #1507
• Finalize Grafana dashboard and data source #1515
• Document Grafana dashboard usage #1521
• Allow Grafana dashboard to display user-defined set of versions #1522 (nice to have)

Supporting storage client changes

• GetMetrics() for a particular app/version/signature #1506 (completed PR GetMetrics() uses app, user, trans #1511)

Supporting Metrics Service

• Design Metrics (HTTP) server for serving metrics data for Grafana dashboard #1512
• Implement Metrics REST API for Iter8 #1514 (dependent on GetMetrics() for a particular app/version/signature #1506)
• Document metrics service feature of Iter8 #1516

Issues related to Iter8

• Refactor ABn service to use traffic contoller instead of its own #1477 (completed PR Refactor A/B/n service to use traffic controller #1493)
• Refactor A/B/n to use storage API #1499 (completed PR Refactor A/B/n service to use traffic controller #1493)
• Update gRPC proto file to remove GetApplicationData #1518 (completed PR Refactor A/B/n service to use traffic controller #1493)
• Support weighted lookup method #1517
• Documentation changes for A/B/n #1513 (in review PR updated abn sdk tutorial docs#95)

[sriumcp]

Assume there is a way to get JSON data for an app, specifically, summary metrics for an app. Display this in a Grafana dashboard.

For starts, it can reflect the information in Iter8 report for ABn testing experiments. Going a step further, may be, for each metric, we can also get the raw values, and plot histograms.

For each metric, histograms, and summaries can be computed at both the user level and transaction.

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In this exercise, for Grafana data source: create a gist, and use simple JSON plugin/Infinity plugin in Grafana as a way to get to this data.

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Go beyond this exercise, once we nail the Grafana viz panels, we can start creating service APIs in Iter8 that supply this JSON data.